John n



(No Model.) 4

J. N HURTY.

PROGESS OF-MAN-UFAGTURING STARCH. No. 395,977. A Patented Jan. 8 ,188-9.

' INVENTOR.

ATTO HN EY NITED STATES PATENT JOHN N. HURTY, OF INDIANAPOLIS, INDIANA.

PROCESS OF MANUFACTURING STARCH.

SPECIFICATION forning part of Letters Patent No. 395377, dated January&1889.

Application filed February 21, 1888. Serial No. 264324. (No speomens.)

To all 2072/0711 it may cancer:

Be it known that I, JOHN N. HURTY, a citizen of the United States,residing at Indianapolis, in the County of Marion and State of Indiana,have invented certain new and useful Improvements in the Process ofManufacturing Starch, of which the following' is a specification.

This invention relates to the manufaeture of starch from maize or Indiancorn and other similar starch-hearing grains, in which the starch isfound naturally associated with gluten and other impurities, from whichit must be separated, its object being to shorten the time necessary toetfect such separation, to secure a g'reater yield of starch than hasheretofore been obtained, to keep sweet and wholesome the starchproduced as well as the by-products, to produce a neutral starch freefrom injurious chemicals, and to economize in the cost of the agentsemployed; and it consists in the process herein described and claimed.

IIeretofore in the most common processes of starch-manufaeture theagents employed for the separation of the impurities and stai ch havebeen acids or alkalies. In some cases the acid has been produced fromthe grain itself by l'ermentation, in the souW process, and in othersthe aeids have been added during the process of man u'facture. Thealkalies are of course always added. In order that my process may befully understood and the differences between it and those heretoforeemployed clearly distinguished, I will describe the starch as it existsin natural associations, and also the processes of separating it fromthe grain. Maize and other cereal grains are conposed of starch, gluten,cellular matter, oil, a certain amount of mineral matter, and of water.Itis eustomary in starchmanufacture to soak the naize or grain beforegrinding, as it grinds more easily after soaking. After grinding thecrushed grain is passed over shakers or sieves, and the finer part,containinginost of the starch, is sifted away 'from the coarser part,called bran or feed Now, this eoarse part is conposed mainly of thecellular matter of the grain, although it also contains some of theother constituents. It is usually used for cattle-feed. The finer partcontains the major portion of the starch and also of the gluten and oil.The mineral matter of the grain is mainly dissolved by the water used socopiously in starch-manufacture The finer part before mentioned, that issifted through the shakers, is accompanied by considerable water, whichholds it in suspension, and it contains all the starch that is to begotten during the subsequent steps of starch-manufaeture. The separationof the starch from the inpurities in this finer part constitutes themost important work of starch-making, and in the manufacture of starchfrom maize and other cereal grains is accomplished by various methods offiotation. The starch has a density or specific gravity of about 1.50,the gluten a density of about 1.35, and the oil about.9l. IIence it willbe readily seen that if these substances be Suspended in water andsubjected to flotation the starch will settle first; but in manufactureit is found that if the grain be ground while in a sweet condition andthe sifted part subjected to flotation in water the entire solid,contents of the sit'ted liquid will deposit together in a doughy mass.This is owing to the adhesive nature of the starch-granules, whichrefuse to separate from the impurities, and hence carry them down.

As starch occurs in nature it is composed of an internal solublesubstance called granulose surrounded by an insoluble envelope orcovering` of what is termed amylo-cellulose or starch-eellulose. Now, inpotatoes or other similar tubers the starch is composed only of theabove-named parts; but in maize or Indian corn, or other cereal grainswhere the starch is associated with -gluten, the outer envelope ofamylo-cellulose is covered with a thin layer of a substance which isadhesive or Sticky when wet. This adhesive coat causes thestarch-granules to stick to the impurities which accompany it in thesifted portion of the grain before described, and even' after chemiealtreatment enough of this coat remains to cause the starch-granules ofcereal grains to stick together in drying, and hence to dry in columnarmasses, technically known as crystals. (Of course potato starch or thestarch made from similar tubers does not so dry, but remains in a moreorless pulverulent condition.)

IOO

If the adhesive coat of the starch-granules of maize or other cerealgrains be ren'oved or rendered non-adhesive, it evident 'from theforegoing descriptions that it can be separated from the gluten and oilwith great ease on account of its greater density. To overcome thisadhesiveness there have heretofore been used acids and alkalies, which,by their violent action, dissolve or tear away part or all of theadhesive coating. In the oldest process the maize or other grain wasfermented by long steeping in hot water, usu ally five days or more,during which rmentation or souring lactic acid and other products were'ormed from the stareh and gluten. The lactic acid reacted on thestarehgranules, partly removing the adhesive coat, and it also dissolvedconsiderable of the gluten. The maize or other grain was then ground,and the ground mass passed over sieves sprnkled with water, whereby thestareh and finer part of the crushed grai n were sifted through and thebran or feed tailed Off the end ot' the shakers to be used ascattle-feed. The finer portion as thus obtained was of courseaceompanied with considerable water, and it was carried to runs orinclined planes and allowed to fiow down these planes or runs, wherebythe starch settled in a more or less firm nass on the bottom of theruns, and the gluten and oil loated away and tailed off the runs, to becarried away to be used as cattle or hog feed. The starch was thenremoved, molded, and dried, as is now practiced.

More modern 'lrocesseshaye been. advanced ol' adding mineral acids tothe si t'ted grain, instead ol' developing the acid by fermentation, andthese processes are ot' greater advantage than the sour process, as theydo not require long steeping; but, like the sour process, the acidsimpair the quality of the stareh and partially remove the adhesive coatof the granules.

Another process now largely used and of greater Value than either thesour or acid processes is the alkaline process, in which caustic soda isadded to the grain, whm'eby the adhesive coating of the stareh-granulesis dissolved and also most of the gluten. This process requires only twoor three days soaking or steeping of the grain, and hcnce the grain isconiparatively sweet when ground. The grain, after steeping, is groundas in the sour process, then likewise passed over shakers or sievessprinkled with water, and the tailings used as cattle-food. The tinerpart that sifts through the moshes ol' the sieves is, as usual,accompanied with consid erable water, and is not earried to the inclinedplanes or runs immediately, but is carried to vats or settling-tubs andallowed to subside. The solid matter sinks to the bottom and clear waterremains above. This water is withdrawn and a solution of caustie sodaadded. This has the eltect ot' dissolving the greater part of the gluteand oil and also the adhesive envelopes ot' the starch-granules, andhence when the liquid is put over the starch planes or runs the starchsettles in a 'firm mass on the bottom and the impurities are :tioatedaway. Instead ot' canstic soda other alkalics or alkaline snbstanceshave been sometimes used, such as potash and soda-ash, carbonates ofsoda and potash,(conmercially known as sal-soda and sal-tartar,) and.lime. These substances are sometimes used alone, sometimes together, orin conjunction with neutral salts; but caustic soda is the most largelyused, as it gives a larger yield of starch and the starch is purer thanwhen lime or alkalinc carbonates are used. The use ot' any ot' thesesubstances gives an alkaline starch and 'forms only a modification ofthe allcaline process.

It maybe added here that no chemicals are needed to puril'y the starcht'rom potatoes or similar tubers, nor do I claim for my process that itis ot' any value in making such starch, because that kind of starch isnon-adhesive, and hence settles free froni impurites, and, moreover, theimpurities found in such substances are all soluble. Therefore wateralone will remove theni, leaving the starch pure.

The beforeanentioned processes are objectionable for many reasons. Thesour process is objectonable on account ot' the foul odor generated bythe t'ern1entati n, which makes every sour-starch works a nuisance tothe community adjacent, and which clings to every product 'ot' suchworks, and because ol? the great less of starch which occurs by changingto lactic acid by fermentation and the foul stench which aecompanies theslop or oltal. The fernuantation also results in the general loss ot'the snbstance ol' the grain by passing into soluble [n-oducts ol' novalue as feed.

The other acid processes are oljectionable on account of the injury tothe machincry and appliances ot' the works by the acid liquors orvapors, the acid characlmof the starch produced neccssitatng adflitonalexpense to neutralize it, (and it' it is not neutr-Llized the liabilityof the starch 'to become moldy is increased,) the altn'aton in characterof the start-h and the less caused by part ot' it being chz'nged toglucose by the acids, and because ot' the character ot' the slop orotl'al, which is, without prtwious preparation, unllt t'or hog or cattlefeed. ln the acid processes where snlphurous aid is used. there is theadditional objeetion of the injury to the workmen by the noxiousacid-vapors which are inevitab] y present. The alkaline process isobjectionable because ot' the great cost ot' the alkali necessary topuril'y the stareh, the alkaline character ot the ott'al, which preventsits full value being obtained as cattlefeed, and the alkaline characterof the starch produced, rendering it unlit t'or use in many nanutacturing Operations, and also because of the less ot' starch by the actionot' the alkali.

My process is free from these objections,

IOO

IIO

t'or in my process neither acid nor alkaline substanccs are used, and atthe same time it gives the maximum yield of neutral starch of a highgrade of purity at the lowest possible cost, besides leaving the feedand offal or slop in a sweet and nutritious condition fit for inmediateuse as cattle and hog feed.

The accompanying drawing represents diagrammatically an apparatus ofcomnon form which maybe advantageously enployed in practicing my processin the preferred way. In said drawing, the portion marked A representsthe vat for steeping the maize or grain; B, the mill for grinding thesame; C,

a pulley by which the same is operated; D,

a shaker for sitting the ground grain; E, the apparatus for Operatingthe shaker; F, a sprinkler for sprinkling the ground grain as it passesover the sieves; G, a trough for receiving the sifted portion; H, a vatin which the starch liquor or milk is allowed to settle; J, an agitatoror stirrer for nixing the contents of the Vat H; K, the starch planes orruns where the starch is deposited; L, a spout or conveyer whichreceives the slop or by-products; M, a conveyer for -receiving thetailings or feed that will not pass through the shaker; N, the faucet orplug to the vat H, through which the supernatant water is drawn off; O,the hopper to the mill B, and P the spout where the ground grain issuesfrom the mill.

I will now dcscribe my process, which I have denominated the sweetprocess, as I prefer to practice it, and give the rationale therefor. Isteep or soak maize or 'Indian corn or other cereal grain in water at atemperature ot' about 130 Fahrenheit for from cig-htecn to twenty-fourhours. It may be steeped longer or at other temperatures, but must notbe allowed to perceptibly ferment. I then grid the stceped grain in aburr or other kind ot' mill, running into said mill a stream of water tofacilitate the grinding and delivery of the grain thercfrom, as is usualin starch-mrks. The ground maize or grain is then passed over sievcs orshakers and sprinkled with water, as is usually practiced instarch-works, and the feed that tails ot't' the shaker can be carri edaway to be used t'or cattle-t'eed. The finer part that sifts through theshaker-cloth is carried to suitable settling-vats. In order to get thehighest yield ot' starch it is necessaryto sprinkle the ground grainwith more water on the shaker than is afterward desirable to pass overthe runs or starch-planes. The liquid that sifts through theshaker-cloth, carrying the finer part of the grain, is therefore allowedto rest in the settling-vats, whereby the starch and inpurities settletogether to the bottom and clear water remains above. This supernatantwater is then drawn ot't', so as to leave a measure of about twenty-livegallons of sediment and water per bushel of maize or grain, which isthen stirred up, and will give a milk of a density of about 1.06. I nowadd to this milk one and two-thirds gallon of a ten-per-cent. solutionof chloride of sodium (or one and onethird pound of chloride of sodiummay be added in substance) per bushel ot' grain, I now agitate the mixedstarch-milk and chloride-ot-sodium solution together for about twentyminutes and then add water to make a total measure of about thirty-threegallons per bushel of the maize or grain. The milk will then have adensity of about 1.045. It may now be passed over the starch planes orruns, and the starch will deposit out of the treated milk in a state ofperfect purity with great ease, while the gluten and other impuritieswill fioat away, sustained by the solution of chloride of sodium, whichhas a density considerably in excess of that of water. The gluten orslop may be used for hog or cattle feed. After 'the starch has beendeposited 011 the runs or starch-planes it may be removed and carriedthrough the usual subsequent Operations of starch -manufacturesuch asmolding, draining, crusting, scraping, and finally drying.

The rationale of my process is as t'ollows: As before stated, thestarch-granules of maize or Indian corn and other cereal grains, wherethe starch-granules. are naturally associated with gluten, are coveredwith a coating that is adhesive when wet. Acids or alkalies partially orwholly remove this coat ing, and hence deteriorate the quality of thestarch, as adhesiveness is one of the most valuable characteristics ofstarch. The other disadvantages of acids and alkalies have already beennoted. I have found that this adhesive coating can be renderednon-adhesive by adding chloride ot sodium in sufficient quantity to thestarch-liquor from unfernented grain, and I have also found that thechloride of sodium does not remove or dissolve any of the adhesivecoating or permanently alter it, but only renders it non-adhcsive whileit is present in the starch-liquor; hence its action is only temporary,and after the starch has been deposited on the runs or starch-planes andthe impurities tloated away the chloride of sodium may be washed out bywater, and the starch will then return to its natural adhesivecondition. The action ot' this coating ot' the starch-granules seems tobe somewhat analogous to that of gelatine, 'for the coating is solublein the presence of acids or alkali es, and also in hot water, and isinsoluble in cold water; but in the latter case it swells up and isadhesive. If chloride of sodium be added to the cold water in properquantity, the eoating will contract and slightly harden and will becomenon-adhesive. I t' now the chloride of sodium IOO IIO

be washed out by fresh cold water, the coating will soften and swell upto its former size and become again adhesive, as before. It will be seenthat the process ot' temporarily rendering the coating noi'-adhesive isthe only one that enables the impurities to be removed from the starchand yet leave the starch in the same condition as it eXists in the maize4 &95,977

and other grain, r'-taining all the advantages that the start-hoti'eercals possesses cwerother sta-hes The importance and Value ofpreserving the adhesive -'atings of the starch-gralules intact will beevident from the consideration that' the quality of adhcsivcncss is ofthe first importance in most of the uses of starcl and from the furthereonsidcratim that the adhesivc coating by its presence protects thestarch-granules from exismosis, and so from shriyeling and drying up.

The starch after depositing on the runs is, in ordinaryStill'Cll-ll'lHIIU'FHCIU'G, always m iXed with water, in order totransfer it to the molding-boxes or settling-cisterns. So it will beseen thatno departure from the ordinary process of man ufacture is nmcssary to completely rest ore the starch to its natural and normalcondition.

The quantity of chloride ot' sodium used in the nnnufacture nay beVaried within wide limits without departing from. my invention, and thestarch-nilk made of Variable densities, according' to the plcasurc ofthe operator; but the quantity and density I have 'amcd have been 'foundto be most et'licacious, more of the chloride of sodium adding nothingto the process and less of it prevcnting the 'full control of thetlotation whichis desired on the star-ch-planes The chloride of sodiunmay also be added before the grain is sit'ted or during the steeping';but: I p-efer to add it' after the grinding and sitting', because itrequires less of the r ag'ent,while the quantity may be more accuratclyknown and regulated, besides which in this way the major portion of thefeed is not at all z'i ffected by the reageut, as it is separated beforethe mixing takes place.

I have found by experience that a solution density of 1.0033 in,starclr-nilk gives the reqnircd control of ilotation on theStflI'Cll-PlllGS, and, as I make the starch-nilk equal thirtythreegallons per bushel ot' maize or grain in the preferred way ofpracticing' Iny process, it will take one and one-third pound ofchloride of sodium to give with this neasure the de- -sired solutionde'sity of 1.0033. The slop or gluten that tails oti' the ends of thestarch planes or runs can be used for cattle or hog feed immediately, asbefore stated. Each bari-el of iteontains the product of about two and,ne-fourth bnshels of grain, and, if desired, may be ctmdeused bydraining to a solid mass, as it has not the stickiness that the productfrom other proccsses has, and hence draius easily. It contains a smallquantity of chloride ot' sodium, which is found bcneticial to hogs orcattle, inproying their condition.

The advantages of my process, as will be readily seen, are the shorttime necessary for the operation, the large yield of starch obtained,the extreme econony in the cost of reagents, the sweet character of thestarch produced, the strcngtlfland beauty of this starch and its'freedom froni injurious chenieals, the nntritimis character of theby-produets and their freedom 'from injurious substanccs, and the 'factthat the solid matter Originally present in the maize or other cerealgrain is preserved, because no 'fermentation has taken place at anystage of the process. The chloride of sodinn also gives a better controlof the llotation of the impurities than has hereto'fore been obtaiued,and confers another property of great Value in stare-hinanufaeture, itbeing an antiseptic, which assists in naintaining the starch andby-products in a sweet condition as long as it is prescnt. It may alsobe obscrved that there can be no offensive odor or in j ury to worlcnienor inachi'ery when this process is used.

Having thus ;fully described my said invention, what I claim as new, anddesire to secure by Letters Patent,

'1. The process of inanufacturing starch, substantially as described,which consists in subjecting the inaize 01' other cereal grain in asubstantially ui''fermented condition to the action of chloride ot'sodiun and separating the gluten and other impurities tllQl''fl'Olll byti otati on.

2. The process of nanufacturing stare-h, substantially as described,which consists in first steeping, grinding, and sitting the maize 01'other cereal grain, and then. subjecting the starch-liquor in asubstantially un'fernented condition to the action of chloride of sodiunand separating the gluten and other npurities therefrom by i'lotation.

S. The process of manufacturing starch, which consists in first stecpingthe grain a sufticient length ot' time to soften but not perceptiblyfernent it, then grinding it, then sifting it under a flow of waterthrough sieves or screens, whercby the starch and finer particles areprecipitated into Vats and the coarser products run oil? untreated to beused for feed, then, after the starch has settled, drawing off thesupernataut water until the liquid remaining is equal to abouttwentyfive gallons for each bushel of grain Originally used, then addingchloride of sodiuin either in solution or otherwise, substantially asdescribed, then mix ing the starch-nilk so treated tl'oroughly, thenadding thereto sufficient water to make the whole quantity aboutthirtythree gallons for each bushel of grain, and then separating thestarch from the other in gredients by settling or passing` over runs andfloating the by-products away, substantially in the manner described.

In witness whereof I have hereunto set my hand and seal, atIndianapolis, Indiana, this 16th day of 1 `ebrua:-y, A. D. 1888.

J OHN N. HURTY. [L. 3.]

XVitncsses:

E. W. I-ERADFORD, W. E. DEVOBE.

IOO

IIO

